Most US dramas fall into one of two categories: critics' darlings such as The Sopranos, The Wire and Mad Men, or high-rating, little-written-about shows such as CSI, or House or Law & Order. Just occasionally a drama manages to become both a critical hit and a ratings phenomenon: think Heroes in its first season, Lost or 24.

The news that Glee, which returns to British screens on E4 tonight, managed to double its ratings from an average of 7m to 13.7m on its return to US television last week means that Ryan Murphy's high-school "dramedy" can claim to be the latest show to achieve this difficult feat.

What makes Glee's success all the more unusual is the fact that Fox's decision to pull the show from the air for four months in January was the sort of risky move that generally backfires. It is rare for the normally fickle American public not just to remember a show but actually bother to watch it if it's been off air for that long.

Second, the signs are that US viewers are finding it increasingly overwhelming to have to commit to a multi-arc story over 22 uninterrupted episodes. Whereas it doesn't matter if you miss the odd episode of a self-contained crime drama such as CSI or The Mentalist, miss an episode of Lost and you are lost yourself. Small wonder, then, that many viewers have voted with their off-buttons rather than sticking with over-plotted dramas such as FlashForward.